A Study to Evaluate the Effect of MK0966 (Rofecoxib) on the Recurrence of Colorectal Adenomas (0966-122)

Inclusion Criteria: * Eligible patients must have undergone a complete colonoscopy within 12 weeks of study entry with removal of all polyps; at least one polyp must have been confirmed a large bowel pre-cancerous polyp (adenoma) by the study pathologist. Exclusion Criteria: * History with a specific hereditary large bowel polyp syndrome * History of a large bowel adenoma before age 35 * Small or large bowel resection or history of inflammatory bowel disease * History of cancer within the five years before enrollment * Expected need for chronic NSAID therapy * Positive test result for stool occult blood * Uncontrolled hypertension, stroke or temporary mini stroke (TIA) within the past 2 years, angina or congestive heart failure with symptoms that occur at rest or with minimal activity * History of myocardial infarction (heart attack), coronary angioplasty, or coronary artery bypass grafting within the past 1 year * Pregnancy